<template>
  <div>
    <!-- 评论列表 -->
    <div
      class="cmt-list"
      :class="{ 'art-cmt-container-1': !isShow, 'art-cmt-container-2': isShow }"
    >
      <van-list
        v-model="loading"
        :finished="finished"
        finished-text="没有更多评论了"
        @load="onLoad"
        :immediate-check="false"
      >
        <!-- 评论的 Item 项 -->
        <div class="cmt-item" v-for="obj in commentsArr" :key="obj.com_id">
          <!-- 头部区域 -->
          <div class="cmt-header">
            <!-- 头部左侧 -->
            <div class="cmt-header-left">
              <img :src="obj.aut_photo" alt="" class="avatar" />
              <span class="uname">{{ obj.aut_name }}</span>
            </div>
            <!-- 头部右侧 -->
            <div class="cmt-header-right">
              <van-icon
                name="like"
                size="16"
                color="red"
                v-if="obj.is_liking === true"
                @click="likeFn(true, obj)"
              />
              <van-icon
                name="like-o"
                size="16"
                color="gray"
                v-else
                @click="likeFn(false, obj)"
              />
            </div>
          </div>
          <!-- 主体区域 -->
          <div class="cmt-body">
            {{ obj.content }}
          </div>
          <!-- 尾部区域 -->
          <div class="cmt-footer">{{ formatDate(obj.pubdate) }}</div>
        </div>
      </van-list>
    </div>

    <!-- 评论区域 -->
    <div>
      <!-- 底部添加评论区域 - 1 -->
      <div class="add-cmt-box van-hairline--top" v-if="isShow === false">
        <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
        <div class="ipt-cmt-div" @click="toggleShowFn">发表评论</div>
        <div class="icon-box">
          <van-badge :content="totalCount === 0 ? '' : totalCount" max="99">
            <van-icon
              name="comment-o"
              size="0.53333334rem"
              @click="commentClickFn"
            />
          </van-badge>
          <van-icon name="star-o" size="0.53333334rem" />
          <van-icon name="share-o" size="0.53333334rem" />
        </div>
      </div>

      <!-- 底部添加评论区域 - 2 -->
      <div class="cmt-box van-hairline--top" v-else>
        <textarea
          placeholder="友善评论、理性发言、阳光心灵"
          v-fofo
          @blur="blurFn"
          v-model.trim="content"
        ></textarea>
        <van-button
          type="default"
          :disabled="content.length === 0"
          @click="pubFn"
          >发布</van-button
        >
      </div>
    </div>
  </div>
</template>

<script>
import {
  commentsListAPI,
  commentLikingAPI,
  commentDisLikingAPI,
  sendCommentAPI,
} from "@/api";
import { timeAgo } from "@/utils/date.js";
export default {
  data() {
    return {
      offset: null, //评论偏移量
      commentsArr: [], //评论数组
      isShow: false, //发布评论区是否展示
      totalCount: "", //总评论数
      content: "", //评论内容
      loading: false,
      finished: false,
    };
  },
  async created() {
    //获取该文章评论数据
    const res = await commentsListAPI({
      artId: this.$route.query.art_id,
      offset: this.offset,
    });
    this.commentsArr = res.data.data.results;
    this.totalCount = res.data.data.total_count;
    this.offset = res.data.data.last_id;

    //判断是否有评论，没有的话直接显示没有
    if (this.commentsArr.length === 0) {
      this.finished = true;
    }
  },
  methods: {
    formatDate: timeAgo,
    //处理评论喜欢点击事件
    async likeFn(bool, obj) {
      if (bool === true) {
        //当前状态为喜欢（红心）
        obj.is_liking = false;
        const res = await commentLikingAPI(obj.com_id);
      } else {
        //当前状态为灰心
        obj.is_liking = true;
        const res = await commentDisLikingAPI(obj.com_id);
      }
    },

    //处理发表评论点击事件
    toggleShowFn() {
      this.isShow = true;
    },

    //评论按钮点击事件
    commentClickFn() {
      //获取当前文章高度
      // const height = document.querySelector(".article-container").scrollHeight;
      // window.scrollTo(0, height);
      // 让原生标签滚动到屏幕的最上面
      document.querySelector(".like-box").scrollIntoView({
        behavior: "smooth",
      });
    },

    //评论-输入框失去焦点事件
    blurFn() {
      //问题：不设置定时的话，当点击发布时，输入框失焦后就会销毁评论2，从而影响评论2组件上的一些功能
      setTimeout(() => {
        this.isShow = false;
      }, 0);
    },

    //评论-发布按钮点击事件
    async pubFn() {
      const res = await sendCommentAPI({
        id: this.$route.query.art_id,
        content: this.content,
      });
      //将返回的评论对象添加到评论数组前面
      this.commentsArr.unshift(res.data.data.new_obj);
      this.totalCount++; //评论数增加
      this.content = ""; //清空输入框
      this.commentClickFn(); //跳转到刚评论位置
    },

    async onLoad() {
      //防止上个页面滚动过，跳到该界面会直接加载，造成数据加载多次的问题
      if (this.commentsArr.length === 0) {
        this.loading = false;
        return;
      } else {
        const res = await commentsListAPI({
          artId: this.$route.query.art_id,
          offset: this.offset,
        });
        this.commentsArr = [...this.commentsArr, ...res.data.data.results];
        this.totalCount = res.data.data.total_count;
        this.offset = res.data.data.last_id;

        //没有评论了
        if (this.offset === null) {
          this.finished = true;
        }

        this.loading = false;
      }
    },
  },
};
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}

/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
